1. Field of the Invention
The present invention relates to an air conditioning system, and more particularly, to an improved accumulator and an air conditioning system using the same.
2. Discussion of the Related Art
Generally, an air conditioning system is a system to heat an indoor room by use of a phenomenon of radiating heat into the surroundings when a refrigerant is condensed, and to cool an indoor room by use of a phenomenon of absorbing heat into the surroundings when a refrigerant is vaporized.
FIG. 1 illustrates one example of an air conditioning system simultaneously performing cooling and heating operations. Referring to FIG. 1, the air conditioning system is provided with an outdoor unit 10 and an indoor unit 20, largely. At this time, the outdoor unit 10 is provided with a compressor 11, a flowing control valve 12, a first expansion device 15, an outdoor heat exchanger 13 and an accumulator 14. Also, the indoor unit 20 is provided with an indoor heat exchanger 22 and a second expansion device 21. Herein, the outdoor and indoor heat exchangers 13 and 22 are respectively adjacent to an outdoor fan 13a and an indoor fan 22a. 
Hereinafter, a connection structure of the aforementioned components by tubes will be described in detail.
First, a first tube 33 connects an outlet 11a of the compressor 11 to a first port 12a of the flowing control valve 12, and a second tube 34 connects a third port 12c of the flowing control valve 12 to an inlet of the accumulator 14. Also, a third tube 35 connects an outlet of the accumulator 14 to an inlet 11b of the compressor 11, and a fourth tube 36 connects a second port 12b of the flowing control valve 12 to one end of the outdoor heat exchanger 13. Then, a fifth tube 31 connects the other end of the outdoor heat exchanger 13 to one end of the indoor heat exchanger 22. At this time, the respective first and second expansion devices 15 and 21 are provided in the fifth tube 31 for being positioned in the indoor unit 10 and the outdoor unit 20. Meanwhile, a sixth tube 32 connects the other end of the indoor heat exchanger 22 to a fourth port 12d of the flowing control valve 12.
In the air conditioning system having the aforementioned structure, the accumulator 14 is formed in a container shape having an empty space therein, such as a cylinder. At this time, the inlet of the accumulator 14 is connected to the second tube 34 for providing a refrigerant, and the outlet of the accumulator 14 is connected to the third tube 35 for discharging the refrigerant. After the accumulator 14 receives, temporarily stores and stabilizes the refrigerant passing through the indoor or outdoor heat exchanger 13 or 22, the accumulator 14 provides only gas phase refrigerant to the compressor 11.
Hereinafter, an operation of the air conditioning system will be described in brief. For reference, a solid arrow indicates a refrigerant flow when cooling the indoor room, and a dotted arrow indicates a refrigerant flow when heating the indoor room.
First, on a cooling operation mode of the air conditioning system, the refrigerant discharged from the outlet 11a of the compressor 11 flows into the outdoor heat exchanger 13 by a guide of the flowing control valve 12. The refrigerant condensed in the outdoor heat exchanger 13 passes through the first expansion device 14, which is completely open, and then expanded in the second expansion device 21. Subsequently, the refrigerant absorbs the surrounding heat in the indoor heat exchanger 22 when the refrigerant expanded in the second expansion device 21 is vaporized in the indoor heat exchanger 22. At this time, the indoor room is ventilated with a cold air surrounding the indoor heat exchanger 22 by the indoor fan 22a, whereby the indoor room is cooled. After cooling the indoor room, the gas phase refrigerant flows into the accumulator 14 by a guide of the flowing control valve 12. At this time, the refrigerant flows into the accumulator 14 at a high pressure. That is, the refrigerant is sprayed to the inner space of the accumulator 14 from the end of the second tube 34. Thus, the gas phase refrigerant flowing to the accumulator 14 is discharged through the third tube 35, and then flows into the inlet 11b of the compressor 11.
On a heating operation mode of the air conditioning system, the refrigerant discharged from the compressor 11 flows into the indoor heat exchanger 22 by a guide of the flowing control valve 12. Then, when the refrigerant is condensed in the indoor heat exchanger 22, the refrigerant radiates condensing heat to the surroundings. At this time, the indoor fan 22a discharges the heat radiated from the indoor heat exchanger 22 to the indoor room, so that the indoor room is heated. After that, the refrigerant condensed in the indoor heat exchanger 22 passes through the second expansion device 21, which is completely open, and then expanded in the first expansion device 15. Herein, the refrigerant expanded in the first expansion device 15 passes through the outdoor heat exchanger 13, the flowing control valve 12 and the accumulator 14, sequentially, and then flows into the inlet 11b of the compressor 11.
However, the related art air conditioning system for cooling or heating the indoor room has the following disadvantages.
If the air conditioning system is continuously operated for heating the indoor room in the winter season at an outdoor temperature of 5° C. or less, the surface of the outdoor heat exchanger 13 is covered with a frost, thereby lowering heat exchange efficiency of the outdoor heat exchanger 13 and the air conditioning efficiency.
According to the frost on the surface of the outdoor heat exchanger 13, the temperature of the refrigerant flowing into the accumulator 14 becomes low, whereby the temperature of the refrigerant flowing into the compressor 11 becomes low. Thus, power consumption for compressing the refrigerant in the compressor 11 increases. Also, the temperature of the refrigerant flowing to the air conditioning system becomes low, whereby it accelerates a phenomenon of generating the frost on the surface of the outdoor heat exchanger 13, thereby lowering the air conditioning efficiency.
On the heating operation mode of the air conditioning system, the refrigerant temperature of the accumulator 14 is low, whereby the refrigerant may be maintained in liquid phase, and the liquid phase refrigerant may flow into the compressor 11. Thus, it causes a noise in the compressor 11, and lowering of compression efficiency, thereby lowering air conditioning efficiency.